[Intel-gfx] [PATCH 05/11] drm/i915: get runtime PM while trying to detect CRT

[Imre Deak]

On Fri, 2014-02-21 at 13:52 -0300, Paulo Zanoni wrote:
> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
> 
> Otherwise we'll read registers that return 0xffffffff, trigger some
> WARNs, think CRT is actually connected (because certain bits are 1),
> and fail the drm-resources-equal testcase!
> 
> Tested on a SNB machine with runtime PM support (which is not upstream
> yet, but is already on my public tree at freedesktop.org, and will
> hopefully eventually become upstream).
> 
> Testcase: igt/pm_pc8/drm-resources-equal
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_crt.c | 26 +++++++++++++++++++-------
>  1 file changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
> index 9864aa1..4c1230c 100644
> --- a/drivers/gpu/drm/i915/intel_crt.c
> +++ b/drivers/gpu/drm/i915/intel_crt.c
> @@ -630,10 +630,13 @@ static enum drm_connector_status
>  intel_crt_detect(struct drm_connector *connector, bool force)
>  {
>  	struct drm_device *dev = connector->dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct intel_crt *crt = intel_attached_crt(connector);
>  	enum drm_connector_status status;
>  	struct intel_load_detect_pipe tmp;
>  
> +	intel_runtime_pm_get(dev_priv);
> +
>  	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force=%d\n",
>  		      connector->base.id, drm_get_connector_name(connector),
>  		      force);
> @@ -645,23 +648,30 @@ intel_crt_detect(struct drm_connector *connector, bool force)
>  		 */
>  		if (intel_crt_detect_hotplug(connector)) {
>  			DRM_DEBUG_KMS("CRT detected via hotplug\n");
> -			return connector_status_connected;
> +			status = connector_status_connected;
> +			goto out;
>  		} else
>  			DRM_DEBUG_KMS("CRT not detected via hotplug\n");
>  	}
>  
> -	if (intel_crt_detect_ddc(connector))
> -		return connector_status_connected;
> +	if (intel_crt_detect_ddc(connector)) {
> +		status = connector_status_connected;
> +		goto out;
> +	}
>  
>  	/* Load detection is broken on HPD capable machines. Whoever wants a
>  	 * broken monitor (without edid) to work behind a broken kvm (that fails
>  	 * to have the right resistors for HP detection) needs to fix this up.
>  	 * For now just bail out. */
> -	if (I915_HAS_HOTPLUG(dev))
> -		return connector_status_disconnected;
> +	if (I915_HAS_HOTPLUG(dev)) {
> +		status = connector_status_disconnected;
> +		goto out;
> +	}
>  
> -	if (!force)
> -		return connector->status;
> +	if (!force) {
> +		status = connector->status;
> +		goto out;
> +	}
>  
>  	/* for pre-945g platforms use load detect */
>  	if (intel_get_load_detect_pipe(connector, NULL, &tmp)) {
> @@ -673,6 +683,8 @@ intel_crt_detect(struct drm_connector *connector, bool force)
>  	} else
>  		status = connector_status_unknown;
>  
> +out:
> +	intel_runtime_pm_put(dev_priv);
>  	return status;
>  }

Similarly to 04/11, this should be part of a power domain get/put for a
new CRT power domain I added in the VLV power domain support patches. On
top of those to solve this issue we'd also need to add an enable/disable
handler for the HSW always-on power well, which would only do a
hsw_disable_package_c8()/hsw_enable_package_c8().

--Imre
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